// 代码题二、基于以下代码完成下面四个练习

const fp = require('lodash/fp')
const cars = [
    { name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true },
    { name: 'Spyker c12 Zagato',horsepower: 650, dollar_value: 648000,in_stock: false },
    { name: 'Jaguar xKR-S', horsepower: 550, dollar_value: 132000, in_stock: false },
    { name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false },
    { name: 'Aston Martin One-77', horsepower: 750, dollar_value: 1850000, in_stock: true },
    { name: 'Pagani Huayra', horsepower:700, dollar_value: 1300000, in_stock: false }
]

// 练习1：使用函数组合fp.flowRight() 获取最后一条数据 in_stock 的属性值
let isLastInstock = fp.flowRight(fp.prop('in_stock'), fp.last)
console.log(isLastInstock(cars))


// 练习2：使用fp.flowRight()、 fp.prop()、 fp.first() 获取第一个car的name
let getFirstCarName = fp.flowRight(fp.prop('name'), fp.first)
console.log(getFirstCarName(cars))


// 练习3: 使用帮助函数_average 重构 averageDollarValue, 使用函数组合的方式实现
let _average = function (xs) {return fp.reduce(fp.add, 0, xs) / xs .length}
let averageDollarValue = fp.flowRight(_average, fp.map('dollar_value'))
console.log(averageDollarValue(cars))


// 练习4: 使用flowRight写一个sanitizeNames()函数,返回一个下划线连接的小写字符串,把数组中的name转换为这种形式:例如:sanitizeNames(["Hello World") => [hello-world"]
let underscore = fp.replace(/\W+/g, '_')
let sanitizeNames = fp.map(fp.flowRight(underscore, fp.prop('name')))
console.log(sanitizeNames(cars))